FFmpegコマンドメモ

随時追加予定

動画の変換
``ffmpeg -i a.mp4 -b:v 8000k -ab 128k -ar 48000 b.mp4``
Input a.mp4
Output b.mp4
動画のビットレート 8000k
音声のビットレート 128k
サンプリングレート 48k

試しに使えそうな動画データセット
American Sign Language Lexicon Video Dataset (ASLLVD)
http://vlm1.uta.edu/~athitsos/asl_lexicon/

例
$ ffmpeg -i scene1-camera1.mov 
ffmpeg version 2.7.1 Copyright (c) 2000-2015 the FFmpeg developers
  built with Apple LLVM version 6.1.0 (clang-602.0.53) (based on LLVM 3.6.0svn)
  configuration: --prefix=/usr/local/Cellar/ffmpeg/2.7.1 --enable-shared --enable-pthreads --enable-gpl --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-libx264 --enable-libmp3lame --enable-libvo-aacenc --enable-libxvid --enable-vda
  libavutil      54. 27.100 / 54. 27.100
  libavcodec     56. 41.100 / 56. 41.100
  libavformat    56. 36.100 / 56. 36.100
  libavdevice    56.  4.100 / 56.  4.100
  libavfilter     5. 16.101 /  5. 16.101
  libavresample   2.  1.  0 /  2.  1.  0
  libswscale      3.  1.101 /  3.  1.101
  libswresample   1.  2.100 /  1.  2.100
  libpostproc    53.  3.100 / 53.  3.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'scene1-camera1.mov':
  Metadata:
    creation_time   : 2008-03-26 03:32:27
  Duration: 00:00:33.93, start: 0.000000, bitrate: 4515 kb/s
    Stream #0:0(eng): Video: mpeg4 (Simple Profile) (mp4v / 0x7634706D), yuv420p, 640x480 [SAR 1:1 DAR 4:3], 4512 kb/s, 60 fps, 60 tbr, 120k tbn, 25 tbc (default)
    Metadata:
      creation_time   : 2008-03-26 03:32:27
      handler_name    : 3ivx MPEG-4 Alias Data Handler
      encoder         : 3ivx MPEG-4 5.0.2
At least one output file must be specified




=====================


$ ffmpeg -i scene1-camera1.mov -an -f image2 -vf fps=fps=60 -qscale 1 -qmin 1 -qmax 1 img_%06d.png
ffmpeg version 2.7.1 Copyright (c) 2000-2015 the FFmpeg developers
  built with Apple LLVM version 6.1.0 (clang-602.0.53) (based on LLVM 3.6.0svn)
  configuration: --prefix=/usr/local/Cellar/ffmpeg/2.7.1 --enable-shared --enable-pthreads --enable-gpl --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-libx264 --enable-libmp3lame --enable-libvo-aacenc --enable-libxvid --enable-vda
  libavutil      54. 27.100 / 54. 27.100
  libavcodec     56. 41.100 / 56. 41.100
  libavformat    56. 36.100 / 56. 36.100
  libavdevice    56.  4.100 / 56.  4.100
  libavfilter     5. 16.101 /  5. 16.101
  libavresample   2.  1.  0 /  2.  1.  0
  libswscale      3.  1.101 /  3.  1.101
  libswresample   1.  2.100 /  1.  2.100
  libpostproc    53.  3.100 / 53.  3.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'scene1-camera1.mov':
  Metadata:
    creation_time   : 2008-03-26 03:32:27
  Duration: 00:00:33.93, start: 0.000000, bitrate: 4515 kb/s
    Stream #0:0(eng): Video: mpeg4 (Simple Profile) (mp4v / 0x7634706D), yuv420p, 640x480 [SAR 1:1 DAR 4:3], 4512 kb/s, 60 fps, 60 tbr, 120k tbn, 25 tbc (default)
    Metadata:
      creation_time   : 2008-03-26 03:32:27
      handler_name    : 3ivx MPEG-4 Alias Data Handler
      encoder         : 3ivx MPEG-4 5.0.2
Please use -q:a or -q:v, -qscale is ambiguous
Output #0, image2, to 'img_%06d.png':
  Metadata:
    encoder         : Lavf56.36.100
    Stream #0:0(eng): Video: png, rgb24, 640x480 [SAR 1:1 DAR 4:3], q=1-1, 200 kb/s, 60 fps, 60 tbn, 60 tbc (default)
    Metadata:
      creation_time   : 2008-03-26 03:32:27
      handler_name    : 3ivx MPEG-4 Alias Data Handler
      encoder         : Lavc56.41.100 png
Stream mapping:
  Stream #0:0 -> #0:0 (mpeg4 (native) -> png (native))
Press [q] to stop, [?] for help
frame= 2036 fps=129 q=0.0 Lsize=N/A time=00:00:33.93 bitrate=N/A    
video:291046kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown